How to fix the healthbar UI at the center of an enemy?

I am currently implementing a health bar system.
On enemy prefab, as a child object, it has UI for healthbar.
And on the healthbar object, I added FacingCamera script which contains the following lines:

LateUpdate()
{
    transform.LookAt(enemyitself.transform.position + cam.forward)
}

The camera angle is like an RTS game, positioned above units.

When the game goes into a play mode, when the enemy goes left side of the camera, the healthbar is positioned slightly left side of the enemy. When the enemy goes right side of the camera, the healthbar is positioned slightly right side of the enemy. When the enemy comes closer to the camera, that is, moves to the bottom side of the camera view, the healthbar overlaps with the enemy.


[blue circles are the enemy units and red boxes are healthbar UI]

Spending hours to solve this but haven’t found the solution yet. Can someone please tell me how to fix the healthbar to be positioned above the center of the enemy’s head?